Previous methods of measuring drug activity have been laborious and complex. Typically, a drug target (the protein to which a drug binds in order to achieve its intended effect) is purified and the drug's effect on target activity over time is measured using increasing concentrations of the drug. Drug kinetics are then determined using standard data manipulations, such as the Scatchard plot or Lineweaver Burke.
However, protein purification and multiple assays make such methods laborious and not conducive to the high throughput generation of data. Further, purified proteins by definition are outside their normal body environment, and the changes in environment can complicate or change the way a protein behaves. This can result in misleading or incomplete information about a drug's activity and kinetics.
What is needed in the art is a method that allows the simultaneous detection of both total target and target-drug binding that would simplify and improve the accuracy of the determination of drug kinetics. It would be preferred if the method allowed such measurements without the prior purification of targets, for example in whole cells. It would be especially preferred if mixed populations of cells, such as are found in whole blood, could be studied without the need for prior separation of cell populations.